/Engine/Plugins/Developer/Concert/ConcertMain/Source/Concert/Public/ConcertSession.h
void CommonRegisterCustomRequestHandler ( const [FName](API\Runtime\Core\UObject\FName) & RequestMessageType, const [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [IConcertSessionCustomRequestHandler](API\Plugins\Concert\IConcertSessionCustomRequestHand-) > & Handler )